07/26/2021
Questions I hear asked often are "What is the Archive folder (or All Mail) folder and what am I supposed to do with it? And why does an Archive button appear on my iPhone instead of Trash?" The answer, well, depends, on whether you're using Google Mail/Gmail, or every other mail system. Non-Google mail hosts: If you're using iCloud, Exchange, Outlook.com, AOL, Yahoo, or any other non-Google mail provider, the Archive folder is just an ordinary folder that has been designated for "messages I don't want in my Inbox any more, but I also don't want to trash." For those who already make their own mail folders for saving mail, this might not serve much purpose, and you probably wish to ignore it....
https://www.ivanexpert.com/blog/2021/07/so-what-is-the-archive-or-all-mail-folder-in-apple-mail-or-outlook-or-gmail-anyway/
"What is the Archive folder (or All Mail) folder and what am I supposed to do with it?" The answer depends on whether you're using Google Mail/Gmail.